So, I've started to read through the Warcraft books in chronological order starting with the War of the Ancients trilogy and it got me thinking. Will I have to play through Warcraft 1-3 in order to get all the lore or will the books fill me in just fine?
You'll have to play Warcraft 3 and it's expac, but 1 and 2 have been retconned to oblivion. You'll learn more about the events of Warcraft 1 and 2 by reading fan sites like wowpedia than you would by actually playing these games (which suck balls btw).